Some elevator cabins simply have air inlet and outlet openings in the lower and upper portion of the elevator cabin body. These inlets and outlets are in direct connection with the outside air.
Many elevator cabins nowadays comprise a motor driven fan mounted on the roof of the cabin. The motor drives a fan blade to draw air from the elevator shaft into the elevator cabin and from there back into the elevator shaft. Conventional cabins have a simple fan opening in the ceiling which serves as an air inlet and sometimes simple ventilation openings in the side walls. The air inlet may be covered by an air duct.
It is a drawback of certain ventilation systems that noise from the operating apparatus of the elevator enters into the elevator cabin through the different ventilation openings.
JP-2001 294 384 discloses an elevator cabin which is fairly well protected against noise from the operating apparatus of the elevator. The elevator cabin has a wall plate rising from the cabin floor, with a ventilation hole in the lower edge area of the wall plate. A fan is installed on a ceiling plate of the elevator cabin. The elevator cabin comprises a vertical air channel extending along the wall plate, delimited by a wall plate portion and by an air channel element having a groove-like section. The air channel element is fixed to the area of the wall plate portion. The upper end of the air channel communicates directly with the elevator shaft. The lower end of the air channel communicates with the cabin through the ventilation hole. The fan pushes air into the elevator cabin. The air travels downwards through the elevator cabin, leaves the elevator cabin through the ventilation hole, travels upwards through the air channel and finally flows from the air channel into the elevator shaft.
Although this elevator cabin is fairly well protected against noise entering through ventilation openings in its side walls, it has certain drawbacks.
One drawback is that the elevator cabin is not protected against noise entering from the ceiling. A drop ceiling in the elevator cabin reduces this noise, apart from the fact that it provides for an esthetic appearance. But if a drop ceiling is employed in the cabin, it is not as easy to obtain a satisfactory ventilation of the elevator cabin, since the drop ceiling restricts the air flow.
Another drawback of this elevator cabin is that the venting is effected by air being fed to the elevator cabin through one inlet only. Hereby the ventilating air will travel with high velocity, so that passengers will be exposed to a draft. Also, the air will not be distributed evenly in the elevator cabin. Further, the direction of the ventilating air from the ceiling to the floor usually is not comfortable for the passengers.